JP2019056038A - Illuminant and method for manufacturing the same - Google Patents

Abstract

To provide a light emitting body capable of emitting light at the uniform amount of light emission in the longitudinal direction and achieving the characteristic of 20 emission length, and a method for manufacturing the same.SOLUTION: The light emitting body consisting of a single crystal manufactured by the EFG method has a size of 280 mm or more in the longitudinal direction. The method for manufacturing the light emitting body comprises: storing dies having a slit and having a width direction arranged in parallel in a crucible; inputting and heating the raw material of the light emitting body in the crucible to prepare a melt; forming a melt pool in an upper portion of the slit; and pulling a seed crystal. A composition formula is represented by (Ce, Mg)RMO(0.0001≤x≤0.3; R is one or more kinds selected from La, Pr, Gd, Tb, Yb, Y and Lu; and M is one or more kinds selected from Al, Lu, Ga and Sc); at least one kind of Ce and Mg is distributed in the longitudinal direction; and at least one kind of atoms selected from Mo, W, Ir, Re, Ru, Pt and Rh are included at 5000 ppm or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light emitter and a method for manufacturing the light emitter.

  Light emitters such as scintillators are used in photon detectors or radiation detectors that detect gamma rays, X-rays, α rays, β rays, neutron rays, and the like. These detectors are expected to be widely applied to positron emission tomography (PET) devices, medical imaging devices such as X-ray CT, various radiation measuring devices for high energy physics, and resource exploration devices.

  As an example of the light emitter used in these detectors, for example, a light emitter having a garnet structure shown in Patent Document 1 is disclosed.

Patent Document 1 discloses a light-emitting body having a garnet structure using light emission from the 4f5d level of Ce ³⁺ and a manufacturing method thereof. The illuminant has the general formula Ce _x RE _3-x M _{5 + y} O _{12 + 3y / 2} (where 0.0001 ≦ x ≦ 0.3, 0 ≦ y ≦ 0.5 or 0 ≦ y ≦ −0.5, M is Al, Lu, 1 or 2 or more types selected from Ga and Sc, and RE is one or more types selected from La, Pr, Gd, Tb, Yb, Y, and Lu). Have. In addition, as a method for producing the light emitter, a Czochralski (CZ) method and an Edge-defined Film-fed. Growth (EFG) method are disclosed.

  Further, for example, Non-Patent Document 1 discloses that when these light emitters are used for high energy physical detectors, a 20 radiation length is desired as a characteristic.

International Publication No. 2015/166999

M. Niiyama, “Hadron physics with GeV photons at SPring-8 / LEPS II”, 2014, EPJ Web of Conferences 73, 08001, p.3

  However, the CZ method has a low crystallization rate of the raw material melt, and is not suitable for mass production of phosphors. Furthermore, due to the diffusion of atoms by convection in the melt, as the crystal growth proceeds, a high-concentration melt remains, and the crystal composition of the luminescent material formed by growth has changed. For example, the segregation coefficient of Ce, which is the luminescent center element, is as small as about 0.05 to 0.3, the Ce concentration increases with crystal growth, and the amount of light emission varies in the crystal pulling direction, leading to a decrease in yield of the light emitters.

  Further, there is no disclosure of specific technical contents on how to produce the luminous body having the characteristic of 20 radiation length by the EFG method, and it has not been realized yet.

  The present invention has been made in view of the above problems, and provides a light emitter capable of emitting light with a uniform light emission amount in the longitudinal direction and capable of realizing a characteristic of 20 radiation length and a method for manufacturing the same. .

  The above problems are solved by the present invention described below. That is, the light-emitting body of the present invention is made of a single crystal, has a longitudinal dimension, and the dimension is 280 mm or more.

In one embodiment of the light emitter of the present invention, the composition formula is (Ce, Mg) _x R _3-x M ₅ O ₁₂ (where 0.0001 ≦ x ≦ 0.3, R is La, Pr, Gd, Tb, Yb, Y , Lu, and M is at least one selected from Al, Lu, Ga, Sc), and at least one of Ce or Mg is in the longitudinal direction. It is preferable that they are distributed.

  Another embodiment of the light emitter of the present invention preferably contains at least one atom of Mo, W, Ir, Re, Ru, Pt, and Rh of 5000 ppm or less (but not including 0 ppm).

  In the method for manufacturing a light emitter according to the present invention, a die having a slit and arranged in parallel in the width direction is accommodated in a crucible, the raw material of the light emitter is put into the crucible and heated, and the raw material of the light emitter is Prepare a melt by melting in the inside, form a pool of melt at the top of the slit through the slit, and contact the seed crystal with the melt at the top of the slit to pull up the seed crystal, consisting of a single crystal, It is characterized by growing a light emitting body having a main surface and a longitudinal dimension of 280 mm or more.

In one embodiment of the method for producing a luminescent material of the present invention, the composition formula is (Ce, Mg) _x R _3-x M ₅ O ₁₂ (where 0.0001 ≦ x ≦ 0.3, R is La, Pr, Gd, Tb, The luminescent material has a garnet structure represented by at least one selected from Yb, Y, and Lu, and M is one or more selected from Al, Lu, Ga, and Sc. It is preferable that one kind is distributed in the longitudinal direction.

  In another embodiment of the method for producing a luminescent material of the present invention, the luminescent material contains at least one atom of Mo, W, Ir, Re, Ru, Pt, and Rh of 5000 ppm or less (but not including 0 ppm). It is preferable that

  According to the illuminant and the method for producing the illuminant according to the present invention, the illuminant can emit light with a uniform amount of light emission along the longitudinal direction. Therefore, it is possible to realize a characteristic of 20 radiation lengths.

Further, in the present invention, the composition formula of the luminescent material is (Ce, Mg) _x R _3-x M ₅ O ₁₂ (where 0.0001 ≦ x ≦ 0.3, R is determined from La, Pr, Gd, Tb, Yb, Y, Lu. 1 or more selected, and M is one or more selected from Al, Lu, Ga, Sc), and at least one of Ce or Mg is distributed in the longitudinal direction of the light emitter by growing by EFG method In addition, the crucible forming material used at the time of manufacturing the light emitter is at least one of Mo, W, Ir, Re, Ru, Pt, and Rh, and the atoms of these forming materials are 5000 ppm or less (however, 0 ppm is not included) It is made to contain in a light-emitting body. By setting the composition and atomic content in this way, a light emitter capable of emitting light with a uniform light emission amount and realizing the characteristics of 20 emission lengths can be manufactured by the EFG method.

It is a perspective view which shows typically the light-emitting body which concerns on embodiment and an Example of this invention. It is a block diagram which shows schematically the manufacturing apparatus of the light-emitting body by the EFG method based on embodiment and the Example of this invention. (a) It is a top view which shows typically an example of die | dye based on embodiment and the Example of this invention. (b) It is a front view of the figure (a). (c) It is a side view of the same figure (a). It is explanatory drawing which shows an example of the seed crystal which concerns on embodiment and an Example of this invention. It is a perspective view which shows typically the positional relationship of a seed crystal and a partition plate in embodiment and the Example of this invention. (a) It is a front view which shows typically the positional relationship of a seed crystal and a partition plate in embodiment and the Example of this invention. (b) It is a front view which shows a mode that a part of seed crystal is fuse | melted in the embodiment and Example of this invention. In embodiment and the Example of this invention, it is a perspective view which shows typically a mode that a light-emitting body grows. It is a perspective view which shows the some light-emitting body based on embodiment and Example of this invention obtained by EFG method partially and typically.

  The first feature of the present embodiment is that the light-emitting body is made of a single crystal, has a longitudinal dimension, and the dimension is 280 mm or more.

The second feature is that the composition formula is (Ce, Mg) _x R _3−x M ₅ O ₁₂ (where 0.0001 ≦ x ≦ 0.3, R is selected from La, Pr, Gd, Tb, Yb, Y, Lu) 1 or more, and M is one or more selected from Al, Lu, Ga, and Sc), and at least one of Ce or Mg is distributed in the longitudinal direction. This is a light emitter.

  The third feature is that the light emitter contains at least one atom of Mo, W, Ir, Re, Ru, Pt, and Rh in an amount of 5000 ppm or less (excluding 0 ppm).

  The fourth feature is that a die having slits and arranged in parallel in the width direction is accommodated in a crucible, and the raw material of the luminous body is put into the crucible and heated, and the raw material of the luminous body is melted in the crucible. Prepare a melt, form a melt pool at the top of the slit through the slit, and bring the seed crystal into contact with the melt at the top of the slit to raise the seed crystal. It is that it was set as the manufacturing method of the light-emitting body which grows the light-emitting body which has the dimension of the longitudinal direction.

The fifth feature is that the composition formula is (Ce, Mg) _x R _3-x M ₅ O ₁₂ (where 0.0001 ≦ x ≦ 0.3, R is selected from La, Pr, Gd, Tb, Yb, Y, Lu) The illuminant has a garnet structure represented by one or more, and M is one or more selected from Al, Lu, Ga, and Sc, and at least one of Ce or Mg is distributed in the longitudinal direction. This is a manufacturing method of the luminous body.

  A sixth feature is a method for producing a luminescent material, wherein the luminescent material contains at least one atom of Mo, W, Ir, Re, Ru, Pt, and Rh of 5000 ppm or less (but not including 0 ppm). It is that.

  According to these illuminants and the method for producing the illuminant, the illuminant can emit light with a uniform light emission amount in the longitudinal direction. Therefore, it is possible to realize a characteristic of 20 radiation lengths.

  In the present invention, the uniform light emission amount means a state in which the variation of the light emission amount over the entire length in the longitudinal direction of the light emitter is within a range of ± 10%.

  The seventh feature is that the light emitter is an As-grown single crystal and a method for manufacturing the light emitter.

  According to these light emitters and the method of manufacturing the light emitter, it is not necessary to grow the crystal of the light emitter so as to have a dimension of 280 mm or more in the longitudinal direction and to perform surface processing such as grinding or polishing. Reduction of the surface processing process can be achieved. Furthermore, since there is no need for grinding or polishing in the light emitter, it is possible to improve the crystallization rate of the raw material, adapt to mass productivity, and improve the yield of the light emitter.

  In the present invention, the As-grown single crystal refers to a single crystal that has not been subjected to surface processing such as grinding or polishing while the crystal is grown.

  Hereinafter, the light emitter according to the present embodiment will be described with reference to FIG. The light-emitting body 2 in the present invention has dimensions in the longitudinal direction (length L direction) as shown in FIG. 1, has a rectangular shape in the plane direction, and has a specific width W of about 10 mm and a thickness. T consists of a single crystal having a size of about 2 mm and a length L which is a dimension in the longitudinal direction of 280 mm or more. A width W of about 10 mm and a thickness T of about 2 mm are desirable because they are highly versatile for use in radiation detectors and can eliminate the polishing allowance after crystal growth. The upper limit of the length L is not particularly limited and can be arbitrarily set. However, in the case of a radiation detector, the required length increases as the radiation energy increases. For example, in the case of absorbing 8 GeV radiation, about 280 mm is a guide for 20 radiation lengths.

Light emitter and second embodiments of the present invention, composition formula _{(Ce, Mg) x R 3} -x M 5 O 12 ( where, 0.0001 ≦ x ≦ 0.3, R is La, Pr, Gd, Tb, Yb, 1 or more selected from Y and Lu, and M is one or more selected from Al, Lu, Ga and Sc). Furthermore, at least one of Ce or Mg is distributed in the longitudinal direction.

  Further, the luminous body 2 contains 5000 ppm or less (excluding 0 ppm) of at least one atom of Mo, W, Ir, Re, Ru, Pt, and Rh.

With such composition and atomic content settings, the light emitter 2 can emit light from the 4f5d level of Ce ³⁺ when irradiated with light in the ultraviolet region of 254 ^nm to 365 nm. Furthermore, the light emitter 2 can cause the light emitter 2 to emit light with a uniform light emission amount in the longitudinal direction by setting the composition and the atomic content.

  Further, even if the length L is set to be longer than 280 mm, a characteristic of 20 radiation lengths can be realized over the length L.

  In the present invention, the uniform light emission amount refers to a state in which the variation in the light emission amount over the entire length in the longitudinal direction (length L) of the light emitter 2 is within a range of ± 10%. In order to be in this state, one or two of Ce or Mg and at least one atom of Mo, W, Ir, Re, Ru, Pt, Rh of 5000 ppm or less (excluding 0 ppm), Distribute over the longitudinal direction.

  The content of at least one of Mo, W, Ir, Re, Ru, Pt, and Rh exceeds 5000 ppm, or Ce or Mg, and at least one of Mo, W, Ir, Re, Ru, Pt, and Rh When the distribution in the longitudinal direction of the atoms is uneven and the fluctuation of the light emission amount over the length L is less than ± 10% or exceeds the range, a uniform light emission amount is obtained over the long length L of 280 mm or more. It becomes impossible. Therefore, the characteristic of 20 radiation length cannot be realized.

  Furthermore, the light emitter 2 is preferably an As-grown single crystal. As-grown single crystal refers to a single crystal that has not been subjected to surface processing such as grinding or polishing in a crystal-grown state. By forming the illuminant 2 with an As-grown single crystal, it is not necessary to perform surface processing such as grinding or polishing on the illuminant 2 that has been grown to have a dimension of 280 mm or more in the longitudinal direction. Reduction of the surface processing of the body 2 can be achieved. Furthermore, since the grinding allowance or polishing allowance in the light emitter 2 is not required, it is possible to improve the crystallization rate with respect to the raw material, adapt to mass productivity, and improve the yield of the light emitter 2. The light emitter 2 has a desired main surface 2a.

  Examples of the radiation inspection apparatus in which the illuminant 2 is used include a resource exploration detector, a high energy physics detector, an environmental radioactivity detector, a gamma camera, a medical image processing apparatus, and the like. As examples of the medical image processing apparatus, applications such as a positron emission tomography (PET) apparatus, an X-ray CT, a SPECT, and a PEM apparatus are preferable. As a form of PET, a two-dimensional type, a three-dimensional type, a time-of-flight (TOF) type, and a depth detection (DOI) type are preferable. Further, these may be used in combination. The light emitter 2 can also be used for a large hadron collision accelerator and a calorimeter.

  Next, the manufacturing apparatus of the light emitter 2 according to the embodiment of the present invention will be described with reference to FIGS. In addition, about the location and content which overlap with description of the said light-emitting body 2, description is simplified or abbreviate | omitted.

  As shown in FIG. 2, the luminous body manufacturing apparatus 1 includes a growth container 3 for growing the luminous body 2 and a pulling container 4 for raising the grown luminous body 2, and grows and grows the luminous body 2 by the EFG method. To do.

  The growth container 3 includes a crucible 5, a crucible drive unit 6, a heater 7, an electrode 8, a die 9, and a heat insulating material 10. The crucible 5 is formed of at least one of Mo, W, Ir, Re, Ru, Pt, and Rh. Among these materials, Mo is preferable because impurities such as Cr can be reduced to an ICP analysis level or lower. The raw material is melted in the crucible 5. The crucible drive unit 6 rotates the crucible 5 with the vertical direction as an axis. The heater 7 heats the crucible 5. The electrode 8 energizes the heater 7. The die 9 is installed in the crucible 5 and determines the liquid surface shape of the melt 21 when the light emitter 2 is pulled up. The heat insulating material 10 surrounds the crucible 5, the heater 7 and the die 9. Both the heater 7 and the heat insulating material 10 are made of carbon.

  Further, the growth vessel 3 includes an atmospheric gas inlet 11 and an exhaust port 12. The atmosphere gas introduction port 11 is an introduction port for introducing argon gas as the atmosphere gas into the growth vessel 3 and prevents oxidation of the crucible 5, the heater 7, and the die 9. On the other hand, the exhaust port 12 is provided for exhausting the inside of the growth vessel 3.

  The pulling container 4 includes a shaft 13, a shaft driving unit 14, a gate valve 15, and a substrate inlet / outlet 16, and pulls up a plurality of flat plate-shaped light emitters 2 grown and grown from the seed crystal 17. The shaft 13 holds a seed crystal 17. Further, the shaft driving unit 14 moves the shaft 13 up and down toward the crucible 5 and rotates the shaft 13 around the lifting direction. The gate valve 15 partitions the growth container 3 and the lifting container 4. The substrate entrance / exit 16 takes in and out the seed crystal 17.

  The manufacturing apparatus 1 also has a control unit (not shown), and the rotation of the crucible drive unit 6 and the shaft drive unit 14 is controlled by this control unit.

  The die 9 is made of Mo and has a number of partition plates 18 as shown in FIG. As an example of the die, FIG. 3 shows a case where there are 30 partition plates 18 and 15 dies 9 are formed. The partition plates 18 have the same flat plate shape and are arranged in parallel to each other so as to form a minute gap (slit) 19 to form one die 9. The slit 19 is provided over almost the entire width of the die 9. Further, since the plurality of dies 9 have the same shape and are arranged in parallel at a predetermined interval so that the width directions thereof are parallel to each other, a plurality of slits 19 are provided. A slope 30 is formed on the upper part of each partition plate 18, and the opening 20 is formed by arranging the slopes 30 so as to face outward. The slit 19 has a role of raising the melt 21 from the lower end of each die 9 to the opening 20 by capillary action.

  The width WD of the die 9 is set in accordance with the width W of the light emitter 2. In the present embodiment, WD = 10 mm is set from the W value. The slit width TS is set to be equal to or less than the thickness T of the light emitter 2.

  The raw material charged into the crucible 5 is melted (raw material melt) based on the temperature rise of the crucible 5 to become a melt 21. The raw material is a compound containing atoms represented by the composition formula of the luminous body 2. An oxide raw material can be used as a starting material. However, when the phosphor 2 is used as a single crystal for a scintillator, it is particularly preferable to use a high-purity raw material of 99.99% or more (4N or more). At the time of production, these starting materials are weighed and mixed so as to have a target composition when the melt 21 is formed. These raw materials are particularly preferably those having as few impurities as possible (for example, 1 ppm or less) other than the target composition.

  A part of the melt 21 enters the slit 19 of the die 9, as described above, rises in the slit 19 based on the capillary phenomenon, and is exposed from the opening 20. The melt pool 22 ( 6 (b)) is formed. In the EFG method, the light emitter 2 grows according to the shape of the melt surface formed by the melt reservoir 22. In the die 9 shown in FIG. 3, since the shape of the melt surface is an elongated rectangle, the flat plate-shaped light emitter 2 is manufactured.

Next, the seed crystal 17 will be described. As shown in FIGS. 2 and 4 to 6, in the present embodiment, as the seed crystal 17, it is preferable to use a seed crystal 17 that is the same as or close to the composition of the light emitter 2. Specifically, the composition formula is (Ce, Mg) _x R _3-x M ₅ O ₁₂ (where 0.0001 ≦ x ≦ 0.3, R was selected from La, Pr, Gd, Tb, Yb, Y, Lu) 1 or more, and M is one or more selected from Al, Lu, Ga, and Sc), and a single crystal containing at least one of Ce or Mg is used as a seed crystal 17. .

  As the seed crystal 17, a flat substrate is used. Further, the seed crystal 17 is arranged so that the planar direction of the seed crystal 17 and the width direction of the die 9 are perpendicular to each other at an angle of 90 °. Further, since the seed crystal 17 and the light emitter 2 are orthogonal to each other at an angle of 90 °, the side surface of the light emitter 2 is shown in FIG. By making the positional relationship between the planar direction of the seed crystal 17 and the width direction of the partition plate 18 perpendicular (by crossing the seed crystal 17 with the partition plate 18), the contact area between the melt 21 and the seed crystal 17 is minimized. It becomes possible to do. Therefore, the contact portion of the seed crystal 17 becomes easy to become familiar with the melt 21, and the occurrence of crystal defects in the light emitter 2 is reduced or eliminated.

  The seed crystal 17 has a substrate shape that can be securely fixed to the substrate holder.

  Next, the manufacturing method of the light emitter 2 using the manufacturing apparatus 1 will be described. First, a predetermined amount of raw material powder (purity: 99.99%) of the luminous body 2 is charged into a crucible 5 in which a die 9 is housed and filled.

  Subsequently, in order not to oxidize the crucible 5, the heater 7 or the die 9, the inside of the growth vessel 3 is replaced with argon gas, and the oxygen concentration is set to a predetermined value or less.

  Next, the crucible 5 is heated to a predetermined temperature by the heater 7 to melt the raw material powder. Since the melting point of the raw material of the luminous body 2 is 2000 ° C. or higher (about 2150 ° C.), the heating temperature of the crucible 5 is set to a temperature higher than the melting point. After a while after heating, the raw material powder melts and a melt 21 is prepared. Further, a part of the melt 21 rises through the slit 19 of the die 9 by capillary action to reach the surface of the die 9, and a melt pool 22 is formed on the slit 19.

  Next, as shown in FIGS. 5 and 6, the seed crystal 17 is lowered while holding the seed crystal 17 at an angle perpendicular to the width direction of the melt reservoir 22 above the slit 19, so that the seed crystal 17 is melted in the melt reservoir 22. Touch the liquid surface. The seed crystal 17 is previously introduced into the pulling container 4 from the substrate entrance 16. In FIG. 5, the melt 21 and the melt reservoir 22 are not shown in order to prioritize the visibility of the slit 19 and the opening 20.

  FIG. 5 is a diagram showing the positional relationship between the seed crystal 17 and the partition plate 18. As described above, the contact area between the seed crystal 17 and the melt 21 can be reduced by making the plane direction of the seed crystal 17 orthogonal to the width direction of the partition plate 18. Therefore, the contact portion of the seed crystal 17 becomes compatible with the melt 21, and crystal defects are less likely to occur in the light-emitting body 2 that is grown and grown. Therefore, the yield of the light emitters 2 can be improved.

  When the seed crystal 17 is brought into contact with the melt surface, the lower part of the seed crystal 17 may be brought into contact with the upper part of the partition plate 18 and melted. FIG. 6B is a diagram showing a state in which a part of the seed crystal 17 is melted. By melting part of the seed crystal 17 in this way, the temperature difference between the seed crystal 17 and the melt 21 can be quickly eliminated, and the occurrence of crystal defects in the light emitter 2 can be further reduced. It becomes.

  Subsequently, the substrate holder is pulled up by the shaft 13 at a predetermined ascent rate, and the pulling up of the seed crystal 17 is started to form the light emitter 2 as shown in FIG. FIG. 7 is an explanatory view showing how the light emitter 2 grows. As described above, the light emitter 2 is grown with the width WD of the die 9 (that is, the width W of the light emitter 2), and the light emitter 2 is pulled up to a predetermined length (length L) at a predetermined speed to form a flat plate shape. The luminous body 2 is obtained.

  Thereafter, the obtained light-emitting body 2 is cooled, the gate valve 15 is opened, moved to the lifting container 4 side, and taken out from the substrate inlet / outlet 16. The external appearance of the obtained flat light-emitting body 2 is shown in FIG.

  As shown in FIGS. 2 and 5 to 8, it is preferable to grow a plurality of crystals of the light emitter 2 from the common seed crystal 17 at the same time because the manufacturing cost of the light emitter 2 per sheet can be reduced. . When simultaneously manufacturing a plurality of light emitters 2, a plurality of dies 9 are accommodated in the crucible 5 and the width directions of the dies 9 are arranged in parallel. By pulling up the seed crystal 17, it is possible to produce a plurality of light emitters 2 as As-grown single crystals having a desired principal surface 2a and a longitudinal dimension L.

  The die 9 including the seed crystal 17 and the partition plate 18 needs to be positioned precisely. Therefore, as shown in FIG. 2, the manufacturing apparatus 1 is provided with a crucible driving unit 6 that rotates the crucible 5 in which the die 9 is installed, and a control unit (not shown) that controls the rotation. The shaft 13 is also provided with a shaft drive unit 14 that rotates the shaft 13 and a control unit (not shown) that controls the rotation thereof. That is, the positioning of the seed crystal 17 with respect to the die 9 is adjusted by rotating the shaft 13 or the crucible 5 by the control unit.

  In addition, it is possible to arbitrarily change the surface direction of the main surface 2a of the light emitter 2 by arbitrarily setting the crystal plane 28 of the seed crystal 17.

  The pulling speed of the luminous body 2 can be set constant from the time when the crystal growth is started by starting the pulling of the seed crystal 17 until the crystal growth is completed with the desired length L. The width W / thickness T This is preferable because the fluctuation ratio of is suppressed.

  In the present invention, the material for forming the crucible 5 is at least one of Mo, W, Ir, Re, Ru, Pt, and Rh. Through 21, the light-emitting body 2 can contain at least one atom of Mo, W, Ir, Re, Ru, Pt, and Rh as it is. However, the content must be 5000 ppm or less (excluding 0 ppm) as described above.

  Therefore, in the present invention, argon gas is used as the atmospheric gas, and both the heater 7 and the heat insulating material 10 are made of carbon. With such a configuration, the atmosphere in the growth vessel 3 becomes reducible, the reaction between the atmosphere and the crucible 5 forming material is suppressed, and the content of the crucible 5 forming material in the light emitter 2 can also be suppressed. The applicant found out after verification. Since the EFG method is adopted in the present invention, the melt 21 is raised from the lower end of each die 9 to the opening 20 through the slit 19 by capillary action. In the present invention, since the melt 21 is thinly raised and supplied through the slit 19 in a state in which the reaction between the atmosphere and the crucible 5 forming material is suppressed, the melt reservoir 22 is always kept in a uniform composition and concentration. It becomes possible to form. Therefore, the pulling growth from the melt reservoir 22 made it possible to realize the formation of a content of 5000 ppm or less and a uniform light emission amount over the length L. Further, with regard to Ce or Mg, a uniform light emission amount in the longitudinal direction can be formed by forming the melt reservoir 22 with a uniform composition and concentration.

  In the verification process, verification was also performed by the EFG method in which the atmosphere gas was a nitrogen atmosphere. However, in this case, for example, Mo reacts with nitrogen, and the reaction promotes the inclusion of the crucible 5 forming material in the luminous body 2. As a result, the Mo content in the luminous body 2 exceeded 5000 ppm, and the characteristics of 20 radiation length could not be realized.

Further, the composition formula of the luminous body 2 is (Ce, Mg) _x R _{3 -x} M ₅ O ₁₂ (where 0.0001 ≦ x ≦ 0.3, R is selected from La, Pr, Gd, Tb, Yb, Y, Lu) 1 or more, and M is one or more selected from Al, Lu, Ga, and Sc), and at least one of Ce or Mg is distributed in the longitudinal direction of the light emitter 2 by growing by EFG method. At the same time, the material for forming the crucible 5 used for manufacturing the light emitter 2 is at least one of Mo, W, Ir, Re, Ru, Pt, and Rh, and the atoms of these materials are 5000 ppm or less (however, 0 ppm is not included) In the luminous body 2 is contained. By setting the composition and the atomic content as described above, the light emitter 2 capable of emitting light with a uniform light emission amount and realizing the characteristics of 20 emission lengths can be manufactured by the EFG method.

  Furthermore, by setting the composition and the atomic content, the light emitter 2 can also realize characteristics with a light emission amount of less than 60000 photons / MeV.

  In addition, this invention is not limited to the above-mentioned embodiment, The change by the structure of the range which does not deviate from the range of the technical idea is possible.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples.

  Hereinafter, the light emitters according to the first and second embodiments and the manufacturing method thereof according to the present invention will be described. As the light emitting device manufacturing apparatus according to this example, the manufacturing apparatus 1 by the EFG method shown in FIG. 2 was used. The material for forming the crucible 5 was made of Mo, argon gas was used as the atmospheric gas, and both the heater 7 and the heat insulating material 10 were made of carbon.

The phosphor to be grown by growth is a single crystal, and the composition formula is Ce _0.05 Lu _2.95 Al ₅ O ₁₂ in both Example 1 and Example 2, and Ce is grown in the longitudinal direction (long) by the EFG method. (L direction).

  As shown in FIG. 1, the light emitter has a dimension in the longitudinal direction and a rectangular shape in the planar direction. The width W was set to 10 mm in Example 1 and 8 mm in Example 2. The thickness T was set to 2 mm in Example 1 and 8 mm in Example 2. Furthermore, the length L was set to 280 mm in both examples.

  None of the light-emitting bodies after the pulled growth was subjected to surface processing such as grinding or polishing, and the As-grown single crystal was used, and the Mo content was measured. The Mo content was measured by ICP-AES. As a result, Example 1 was 221 ppm and Example 2 was 13 ppm.

  On the other hand, as Comparative Example 1 and Comparative Example 2, a light emitter was manufactured using the manufacturing apparatus 1 by the EFG method shown in FIG. The only difference between the two comparative examples from the previous examples is that the atmosphere gas was changed to a nitrogen atmosphere. Otherwise, Comparative Example 1 was the same as Example 1, and Comparative Example 2 was the same as Example 2. . As a result of measuring the Mo content of the grown phosphor that was pulled up, Comparative Example 1 was 5005 ppm, and Comparative Example 2 was 5011 ppm.

  The light emitters of Examples 1 and 2 and Comparative Examples 1 and 2 were both irradiated with light in the ultraviolet region of 254 nm to 365 nm, and it was confirmed whether or not the 20 radiation length characteristic was realized. As a result, it was confirmed that 20 radiation lengths were achieved in Examples 1 and 2. On the other hand, in Comparative Examples 1 and 2, it was confirmed that 20 radiation length was not achieved.

  Next, the light emitter of Example 3 and the method for manufacturing the same according to the present invention will be described. As the light emitting device manufacturing apparatus according to Example 3, the manufacturing apparatus 1 by the EFG method shown in FIG. 2 was used. The material for forming the crucible 5 was made of Mo, argon gas was used as the atmospheric gas, and both the heater 7 and the heat insulating material 10 were made of carbon.

The phosphor to be grown is a single crystal and its composition formula is Mg _0.0006 Ce _0.0294 Lu _2.97 Al ₅ O _12, and Mg and Ce are grown in the longitudinal direction (length L direction) of the phosphor by pulling and growing by the EFG method. Distributed over.

  As shown in FIG. 1, the light emitter has a dimension in the longitudinal direction and a rectangular shape in the planar direction. The width W was set to 10 mm, the thickness T was set to 2 mm, and the length L was set to 300 mm.

  The light-emitting body after the pulled growth was not subjected to surface processing such as grinding or polishing, and was made as an As-grown single crystal.

  On the other hand, as Comparative Example 3, a light-emitting body made of a single crystal was produced by the CZ (Czochralski) method. The difference between Comparative Example 3 and Example 3 is that the method for producing the light emitter is the EFG method or the CZ method, and the composition formula, width W, thickness T, and length L of the light emitter are the same.

  The light emitters of Example 3 and Comparative Example 3 were both irradiated with light in the ultraviolet region of 254 nm to 365 nm, and fluctuations in the light emission amount (photon / MeV) over the length L were confirmed. At the same time, changes in Ce concentration (mol%) and Mg concentration (mol%) over the length L were also confirmed by ICP-AES.

  As a result, it was confirmed that both of the illuminants had characteristics with a light emission amount of less than 60000 photons / MeV over a length L = 300 mm. However, in Comparative Example 3, the light emission amount is 30000 photons / MeV at the L = 10 mm portion from the end of the light emitter, the light emission amount is 27000 photons / MeV at the L = 100 mm portion, and the light emission amount is 15000 photons / MeV at the L = 200 mm portion. , L = 300 photons / MeV at 300 mm. From the above results, in Comparative Example 3, it was confirmed that the variation of the light emission amount over the entire length in the longitudinal direction of the light emitter was not within ± 10%, and a uniform light emission amount could not be realized in the longitudinal direction. It was done.

  On the other hand, in Example 3, the light emission amount 30500 photons / MeV at the L = 10 mm portion from the end of the light emitter, the light emission amount 30200 photons / MeV at the L = 100 mm portion, the light emission amount 29500 photons / MeV at the L = 200 mm portion, The light emission amount at L = 300 mm portion was 30400 photons / MeV. From the above results, in Example 3, the variation in the light emission amount over the entire length in the longitudinal direction of the light emitter is within a range of ± 10%, and a uniform light emission amount in the longitudinal direction can be realized. confirmed.

  Further, the Ce concentration and the Mg concentration in Example 3 are as follows: Ce concentration is 0.99 mol%, Mg concentration is 0.022 mol%, L concentration is 0.022 mol%, and Ce concentration is 1.00 mol% at the L = 100 mm portion from the edge of the light emitter. The Mg concentration was 0.022 mol%, the L concentration was 200 mm, the Ce concentration was 1.01 mol%, the Mg concentration was 0.022 mol%, the L concentration was 300 mm, the Ce concentration was 1.01 mol%, and the Mg concentration was 0.022 mol%.

  On the other hand, the changes in Ce concentration and Mg concentration in Comparative Example 3 were Ce concentration of 0.12 mol%, Mg concentration of 0.002 mol% at L = 10 mm portion from the edge of the light emitter, Ce concentration of 0.24 mol% at L = 100 mm portion, The Mg concentration was 0.005 mol%, the L concentration was 200 mm, the Ce concentration was 0.68 mol%, the Mg concentration was 0.009 mol%, the L concentration was 300 mm, the Ce concentration was 2.20 mol%, and the Mg concentration was 0.029 mol%.

  From the above results, it was confirmed that both the variation value of Ce concentration and the variation value of Mg concentration in the longitudinal direction were larger in Comparative Example 3 than in Example 3.

DESCRIPTION OF SYMBOLS 1 Light-emitting body manufacturing apparatus 2 Light-emitting body
2a Main surface 3 Growth vessel 4 Lifting vessel 5 Crucible 6 Crucible drive 7 Heater 8 Electrode 9 Die
10 Insulation
11 Atmospheric gas inlet
12 Exhaust vent
13 Shaft
14 Shaft drive
15 Gate valve
16 Board entry / exit
17 seed crystals
18 Partition plate
19 Slit
20 opening
21 Melt
22 Melt pool
28 crystal plane
30 Slope L Length of illuminant W Width of illuminant T Thickness of illuminant
TS slit width
WD die width

Claims (8)

  A light-emitting body made of a single crystal and having a dimension in the longitudinal direction and having a dimension of 280 mm or more. Composition formula is (Ce, Mg) _x R _3-x M ₅ O ₁₂ (where 0.0001 ≦ x ≦ 0.3, R is one or more selected from La, Pr, Gd, Tb, Yb, Y, Lu, M Is one or more selected from Al, Lu, Ga, and Sc).
The light-emitting body according to claim 1, wherein at least one of Ce and Mg is distributed in the longitudinal direction.   The light emitter according to claim 1 or 2, containing at least one atom of Mo, W, Ir, Re, Ru, Pt, and Rh in an amount of 5000 ppm or less (excluding 0 ppm).   The luminescent material according to claim 1, wherein the luminescent material is an As-grown single crystal. A die having a slit and arranged in parallel in the width direction is housed in a crucible,
The raw material of the luminous body is put into a crucible and heated, and the raw material of the luminous body is melted in the crucible to prepare a melt,
A melt pool is formed at the upper part of the slit through the slit,
A method of manufacturing a light emitting body, in which a seed crystal is brought into contact with the melt above the slit and the seed crystal is pulled up to grow a light emitting body made of a single crystal and having a major surface and a longitudinal dimension of 280 mm or more. Composition formula is (Ce, Mg) _x R _3-x M ₅ O ₁₂ (where 0.0001 ≦ x ≦ 0.3, R is one or more selected from La, Pr, Gd, Tb, Yb, Y, Lu, M Is one or more selected from Al, Lu, Ga, and Sc), and the light emitter has a garnet structure represented by:
The manufacturing method of the light-emitting body according to claim 5, wherein at least one of Ce and Mg is distributed in the longitudinal direction.   The phosphor according to claim 5 or 6, wherein the phosphor contains 5000 ppm or less (excluding 0 ppm) of at least one atom of Mo, W, Ir, Re, Ru, Pt, and Rh. Production method.   The method of manufacturing a light emitter according to claim 5, wherein the light emitter is an As-grown single crystal.

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